1. Field of the Invention
An object of the present invention is an aircraft nose comprising a protective shield. This protective shield is located between, on the one hand, a cabin or cockpit in which the pilots are located and, on the other hand, a radome in the front of the aircraft in which certain detection devices such as radar antennas are located.
It is an aim of the invention, in the case of large aircraft, to efficiently protect a cabin, a flight deck or even a vital compartment of the aircraft from frontal impact at high speed. Such projection results essentially from forceful impact by flying objects or creatures on the front of the aircraft. At high speed, the radome located in front of the aircraft is perforated in its central part by the projectile encountered, the devices inside the radome are destroyed and the projectile continues traveling up to the compartment in which the pilot or pilots are placed. The pilot or pilots may then be seriously injured. It is possible that, in the zone located beneath the floor of the cabin, facing the bay, in a vital compartment of the aircraft, there will be other devices that could be damaged by this impact. When the projectile reaches the aircraft more or less on the nose side, the inclination of the fuselage at this position averts perforation.
To prevent such accidents, a shield is interposed between, on the one hand, the cabin in which the pilot is placed or the vital compartment of the aircraft and, on the other hand, the radome of the aircraft placed in front of the aircraft.
2. Description of the Prior Art
Prior art shields are constituted in such a way as to be made in the form of assembled panels adjoining one another. Indeed, at high altitude, the atmospheric pressure is low. To avoid a situation where the aircraft passengers lack air, the cabin is tightly sealed and, because of the very low external pressure, it is deemed to be pressurized. This means that the structures of the aircraft are subjected to internal pressure forces having an effect similar to that of an inflation. This inflation is produced everywhere in the aircraft, and especially at the front of the aircraft, on a front frame of the cabin bearing the shield. This frame, which is initially plane, gets deformed. This shield structure in the form of panels is then put to use to adapt to this deformation while at the same time keeping the qualities of tight sealing and protection given by the shield.
However, for large aircraft, the shield must fulfill other functions. In particular, it must be light and resistant, and must furthermore easily lend itself to mounting and dismounting during aircraft maintenance. The standard provides that the shield must withstand impact by flying objects of a weight of four pounds launched at speeds of 180 m/second. From this viewpoint, the approach using multiple panels proves to be less efficient and less practical to implement than a rigid and resistant panel. We are then confronted with the following problem, which is that of making a large-sized rigid and resistant panel to be mounted on a structure that is itself deformable.